European Portuguese, like other Romance languages, displays a great amount
of word order variation. Out of the six logically possible permutations
between Subject, Verb and Complement in a transitive sentence, five are
possible: SVO, VSO, VOS, OVS and OSV.

The primary goal of this book is to provide an analysis of the several
positions where the subject may surface in European Portuguese. Departing
from an architecture of the clause as sketched in early minimalist work,
containing two subject-related functional categories above VP (AgrP and
TP), it is shown that the subject may surface in all potential landing
sites: Spec,AgrP, Spec,TP and Spec,VP. Moreover, just like any other
argument of the clause, it is claimed that subjects also have the
possibility of surfacing in a left-dislocated position, arguably adjoining
to the clause's left periphery.

It is shown that there is no free variation. Each of these positions may be
occupied by the subject, only if two requirements are met: i) the position
is made available by syntax; ii) the position does not violate any
interface condition.

In other words, the following model is argued for: syntax generates
legitimate outputs. At the interface levels, each output may be selected or
filtred out, according to requirements of the interface.

The picture emerging from the proposal made in this book is the following:
syntax proper does not need to refer to conditions best placed at the
interface. All that is needed from syntax is that it generates an array of
well-formed outputs. Such outputs may be evaluated a posteriori by each of
the interfaces. If they meet requirements of the interface, they are
selected as legitimate. If, on the contrary, some interface condition is
violated, they are ruled out. Under this approach, three independent
results are derived: i) an explanation is found for the patterns of word
order variation; ii) syntax proper may be reduced to its own tools, not
having to manipulate semantic, discourse or prosodic variables; iii) the
intuition that European Portuguese is an SVO language is derived: this word
order corresponds to the one in which the subject occupies the only
specifier position in which the other interfaces play no role.

João Costa is Assistent Professor of Linguistics at the University of
Lisbon, Portugal.